Jack moans and tries not to move in any way to give away what they are doing, but with a head full of thoughts about sucking his lover and the shove of an ever hardening cock he's having a hard time.

Jack's hard and that hand sliding across his pants causes his whole body to buck without warning. His hands are almost to slick to hold on and for a moment he's flailing with fear that he's going to fall right off this cock they're riding.

it's probably the firm hold on his crotch that keeps him from upsetting and falling off like a fool. He's left panting heavily from arousal and now fright. "Can't you teleport or something?"

Jack gasps the words while trying to catch his breath.